This allows building (and running) codec_unittest for android.
This explicitly needs to go at the end of the LDFLAGS, since both
this and -lgtest etc. are static libraries, and code in gtest
relies on the STL. Since this explicitly needs to be at the end,
a separate makefile variable is added for it.
This fixes building of gtest on msvc.
See e.g. http://stackoverflow.com/questions/8274588 for
more discussion on the matter.
This is only required on MSVC 2012 - gtest itself (in the cmake
files) adds -D_VARIADIC_MAX=10 to the build when building using
MSVC 2012, but we don't know the MSVC version at the make stage
here. Since the gtest tuple support isn't used at all, it's
simpler to just disable it altogether than to try to add
-D_VARIADIC_MAX=10.
The main purpose is to make sure that the build doesn't fail
if the build directory contains the gtest subdirectory, although
the unittests also could be run on a device.
One doesn't need to run the ndk-build command from within the
jni subdirectory, calling it from the project top level directory
works just as well.
Also remove an unnecessary step of cd ../../../.. at the end -
since all make commands are run in a subshell, we don't need to
restore the current working directory afterwards.
MSVC doesn't export any functions at all by default, contrary to
gcc which exports all global functions by default.
Doing the same for linux/OS X isn't too hard, but they use yet
two other, different syntaxes for the corresponding symbol file.
This is enabled for platforms/compilers that support the -MMD
option, which creates a dependency file named out.d when compiling
to a file named out.o, only including local, not system headers.
The additional -MP option adds phony targets for all included
headers, to avoid having make error out due to "no rule to make
target foo.h" if a header is renamed/removed.
This makes sure that all the right files are rebuilt if a header
is changed, avoiding the need for a full rebuild if only a few
files are affected.
Don't enable threading globally since the MSVC/ARM build target
(neither windows phone nor windows rt) doesn't support the normal
windows threading functions.
This makes sure that e.g. "make clean" actually removes
the built exe files, and avoids relinking the exe files each
time make is run when cross compiling from linux to windows.
(Make on windows seems to have an exception that knows to skip
rebuilding the 'h264enc' target if 'h264enc' doesn't exist but
'h264enc.exe' does, but this exception doesn't work on normal
unix make.)
The library uses this define to enable OS X specific functionality
in general, even if none of those snippets actually have been
strictly required so far.